The Illinois Environmental Protection Agency and Department of Public Health are advising individuals to be cautious if they are planning activities on Illinois lakes and rivers, now and throughout the summer. Water conditions are ideal for blue-green algae growth. Blue-green algae (also known as cyanobacteria) are microscopic organisms that naturally occur in lakes and streams. Rapid growth of algae is referred to as a “bloom.” While most blue-green algae are harmless, some can produce toxic chemicals that cause sickness or other health effects in people and pets, depending on the amount and type of exposure.
- looks like spilled, green or blue-green paint;
- has surface scums, mats, or films;
- is discolored or has green-colored streaks; or
- has greenish globs suspended in the water below the surface.
Illinois Environmental Protection Agency Harmful Algal Bloom website:
https://www2.illinois.gov/epa/topics/water-quality/monitoring/algal-bloom/Pages/default.aspx
USEPA’s Cyanobacterial Harmful Algal Blooms website:









